This invention relates to an airbag module for a motor vehicle.
Such airbag module comprises a gas bag, which is inflatable by means of a gas generator for the protection of a person, and at least one vent opening through which gas originating from the airbag module (which was released by the gas generator for inflating the gas bag) can escape (exit) from the airbag module, and furthermore a device for controlling the outlet cross-section of the vent opening, which includes at least one covering member with which the vent opening can be covered, in order to at least partly close the same, and which furthermore includes an actuating mechanism which cooperates with the covering member, in order to vary the outlet cross-section of the vent opening.
With such a device it is possible to selectively control the so-called venting of a gas bag, i.e. the draining of those gases which were released by a gas generator and introduced into the gas bag for the protection of a vehicle occupant, for example in dependence on the kind and severity of an accident and on the size and/or the weight and/or the seating position of the person to be protected, which can be detected in particular by means of sensors.
It presently is provided that the actuating mechanism includes a gas source and an element inflatable by means of the gas source, which during inflation cooperates with the covering member such that it effects a change in the outlet cross-section of the vent opening.
The gas source for example can be ignited pyrotechnically (sensor-controlled) and then releases a gas with which the inflatable element is filled, whereby it cooperates with the covering member associated to the vent opening or acts on the same, so that the outlet cross-section is not changed in the end.
According to one variant, the covering member can originally cover the vent opening, so that the actuating mechanism is provided, in order to (at least partly) clear the vent opening by acting on the covering member. Alternatively, the vent opening can be exposed originally and the covering member can be acted upon by the actuating mechanism such that the vent opening is (at least partly) closed. It is also possible that the covering member initially partly covers the vent opening and the degree of coverage is changed by the action of the inflatable element.
An airbag module as mentioned above is known from DE 10 2005 039 418 A1.
In such airbag module, one difficulty consists in the suitable fixation of the inflatable element which serves for controlling the outlet cross-section of the vent opening.